INSTRUMENT MANUAL
VACUUM GAUGE MODEL MM200
160Phone:(215) 947-2500 fax:(215) 947-7464 e-mail:sales@televac.com web site:www.televac.com
MM-200_im REV M
Page 75 of 160
TELEVAC
COMMUNICATIONS
(See also "BRE", "BRO", "SRE", and "SRO" above under "Burst" commands).
All of these commands can be stored so that they will be in effect at power up.
"AD<cr>"
1. Add delay for RS485 operation. This command adds a slight delay to the initial
response to any RS485 command. It is required for proper operation when the
RS485 communications hardware of the host cannot handle the immediate
response that the MM200 is capable of providing. Some converters such as the B
& B model 485TBLED, when using the transmitted signal to control the direction of
the signal, are not ready to accept a response as quickly as the Modular Unit
responds, causes contention and signal garbling.
"BE<cr>"
2. Blank the echo. This command causes the modular unit not to echo commands.
However, the appropriate responses to the commands will still be given.
"AT<cr>".
3. Add command input timeout. This command causes a 50 millisecond time out
to be inserted when receiving a command string. If there is a delay of 50
milliseconds or more between any two bytes of a command string, the received
portion of the command will be ignored. The input buffer will be reset and ready to
receive a new command (or RS485 address).
"CT<cr>"
4. Cancel the command input time out. (See "AT<cr>" above.
"EE<cr>"
5. Enable the echoing of the command characters. This command causes all
command characters to be echoed to the host. This is the default setting for a new
unit. It can be stored, in which case the stored "BE" command is canceled.
Echoed commands are very useful when someone is checking out or operating the
unit from a dumb terminal, or a PC with communications software.
"G2<cr>"
6. Go to the RS422 mode. This mode is identical to the RS232 mode, except that
communications is through the RS422/RS485 port. There will be no response on
RS232. If any additional characters are sent via RS232 the mode will revert to RS
232.
"G4<cr>"
7. Go to the RS485 mode. This command causes the modular unit to go into the
RS485 mode. See "RS485 HOST COMMAND SET". There will be no response
on RS232. If any additional characters are sent via RS232 the mode will revert to
RS 232.